import sys

string = sys.stdin.readline().strip()
n = len(string)

letter = [[] for i in range(26)]
index = []

for i in range(n):
    ascii = ord(string[i])
    if ascii >= 65 and ascii <=90:
        letter[ascii - 65].append(string[i])
    elif ascii >= 97 and ascii <=122:
        letter[ascii - 97].append(string[i])
    else:
        index.append(i)

# print(letter)
result = []
for l in letter:
    if l:
        result.extend(l)
# print(result)
for i in index:
    result.insert(i, string[i])

# print(result)

print(''.join(result))